A powered sliding device of a vehicle sliding door including a sliding door slidably mounted on a guide rail provided on a vehicle body, a wire cable coupled to the sliding door, and a power unit for pulling the wire cable in a door-opening direction and a door-closing direction with a motor power so as to slide the sliding door in the door-opening direction and the door-closing direction is conventionally known.
FIGS. 1A and 1B show a conventional basic arrangement relationship of a vehicle body A and a sliding door B. A lower rail D is fixed in the vicinity of a lower part of an ingress/egress aperture C of the vehicle body A, and a center rail E is fixed on a quarter panel of the vehicle body A. When the ingress/egress aperture C is blocked with the sliding door B, the lower rail D is isolated from the outside of the vehicle with the sliding door B and protected from rainwater. However, the center rail E is substantially always exposed to the outside and is not protected from rainwater.
The sliding door B has a lower roller bracket F and a center roller bracket G which are slidably engaged with the lower rail D and the center rail E, respectively. The roller brackets F and G are pivotally mounted on the sliding door B, preferably. The sliding door B moves in the door-opening direction and the door-closing direction through the slidable engagement of the roller brackets and the rails.
The prior art powered sliding device is classified into four types in accordance with the arrangement position. FIGS. 2A and 2B show the first type (refer to U.S. Pat. No. 5,203,112). A power unit H of the first type powered sliding device is provided under the floor panel of the vehicle body in the vicinity of the ingress/egress aperture C. A wire cable J which moves the sliding door B with the power of the power unit H is substantively formed into a loop, passing through the lower rail D, and is coupled to the lower roller bracket F. With such configuration, the sliding door B is slidable with the movement of the wire cable J by the power of the power unit H.
In the second type device disclosed in U.S. Pat. No. 5,913,563, as shown in FIGS. 3A and 3B, the power unit H is provided in an interior space K of the quarter panel. The loop shaped wire cable J is passed through the center rail E, and is coupled to the center roller bracket G of the sliding door B.
In the third type device shown in FIGS. 4A and 4B, the power unit H is provided in the interior space K similar to the second type device (refer to U.S. Pat. No. 4,862,640). The wire cable of the third type device is divided into a door-opening cable J′ and a door-closing cable J″, and the opening cable J′ is guided by the lower rail D to be coupled to the lower bracket F of the sliding door B, and the closing cable J″ is guided by the center rail E to be coupled to the center bracket G of the sliding door B.
In the fourth type device, as shown in FIGS. 5A and 5B, the power unit H is provided inside the sliding door B (Japanese Patent Laid-Open No. 2001-336352). The wire cable of the fourth type device is also divided into the opening cable J′ and the closing cable J″. The opening cable J′ is fixed to a rear end portion of the center rail E by way of the center bracket G, and the closing cable J″ is fixed to a front end portion of the center rail E by way of the center bracket G.
In the first type device, an installation space for the power unit H must be defined under the floor panel of the vehicle body, and thus the first type device has a disadvantage that the vehicle interior space becomes narrow. Further, a path for the wire cable J which has to be provided under the floor panel narrows the vehicle interior space. In addition, since a part of nearly more than half of the wire cable J is difficult to be recognized by the eye or to touch it by the hand, it is difficult to carry out maintenance.
In the second type device, the power unit H is provided in the interior space K of the quarter panel, and thus the second type device has a disadvantage, similar to the first type device, that the vehicle interior space becomes narrow. Further, a pulley for guiding the wire cable J which has to be provided on each of the front and back ends of the center rail E further narrows the vehicle interior space. Additionally, in the second type device, even if the sliding door B is in the closed state, the wire cable J is permanently positioned in the center rail E over the entire length. The center rail E is, in effect, always exposed to the outside and thus is not protected from rainwater. Therefore, the second type device has a disadvantage that, due to the rainwater falling on the center rail E, the grease and the like applied to the wire cable J may come off, causing the quarter panel to be dirty. There is also a problem that dust may adhere on the wire cable J permanently positioned in the center rail E. In addition, similarly to the first type, since a part of nearly more than half of the wire cable is difficult to be recognized by the eye and to touch it by the hand, it is difficult to carry out maintenance.
In the third type device, if the sliding door B is in the closed state, the closing cable J″ is not, in effect, present in the center rail E, and thus problems of quarter panel becoming dirty, and dust adhering on the closing cable J″ are alleviated. However, the power unit H is provided in the interior space K of the quarter panel and a pulley must be provided at the front end of the center rail E to guide the closing cable J″. Thus, there is a disadvantage that the vehicle interior space becomes narrow, as in the first and the second type. In addition, since both of the door-opening cable J′ and the door-closing cable J″ are difficult to be easily recognized by the eye and to touch them by the hand, it is troublesome to carry out maintenance, similarly to the first type and the second type.
In the fourth type device, the power unit H is provided inside the sliding door B, and there is no need to attach a pulley to the center rail E, and thus there is an advantage of effectively utilizing the vehicle interior space. However, even if the sliding door B is in the closed state, one part of the opening cable J′ is permanently located in the center rail E, and thus the fourth type device has a disadvantage that the grease and the like applied to the opening cable J′ may come off, causing the quarter panel to become dirty. There is also a problem of dust adhering on the door-opening cable J′ that is permanently positioned in the center rail E.